1. Technical Field
The present invention relates to a liquid droplet ejection head for ejecting a liquid droplet and an image forming apparatus having the liquid droplet ejection head.
2. Related Art
There is known an image forming apparatus for ejecting a liquid droplet from a nozzle in a state that a liquid is circulated in an ejector to prevent the increase of viscosity of a liquid in the vicinity of the nozzle
In more detail, when ejection of a liquid droplet is paused and no liquid droplet is being rejected from a nozzle, a liquid is also circulated in the same amount as that of the liquid circulating in an ejector when a liquid droplet is ejected from the nozzle. With this operation, the increase of viscosity of the liquid in the vicinity of the nozzle can be prevented.
Further, there is also an image forming apparatus in which a liquid droplet is ejected from a nozzle at every predetermined time regardless of image formation (preliminary ejection) to prevent the increase of viscosity of a liquid in the vicinity of a nozzle
However, when the preliminary ejection is performed, a liquid is wastefully used (waste liquid) in no relation to image formation. To cope with the above problem, the intervals of the preliminary ejection can be increased by circulating a liquid in an ejector, thereby the amount of the waste liquid can be reduced. However, recently, it is desired to reduce the amount of the waste liquid more than ever to increase the added value of an image forming apparatus.